While each possesses the natural talent to lead a franchise, questions persist about their fundamentals and ability to transition to the pro game.

For Gabbert and Newton, the transition from the spread offense to a pro-style system will dominate the conversation. Both directed wide-open offenses that extensively featured the shotgun formation, and their inexperience working from under center could pose major issues down the road.

Unlike taking direct snaps while facing the coverage, the process of executing conventional drops with play-action forces a quarterback to lose sight of the defense before finding his reads. Even though it seems like such a minor detail, this is a pivotal part of the drop-back game, and teams have to be convinced that Gabbert and Newton have the ability to operate in that kind of system.

When looking at Mallett and Locker, their biggest concerns revolve around inconsistent fundamentals and mechanics. Although their strong arms fit the bill, their undisciplined footwork frequently results in errant throws.

For Locker, in particular, his inability to play with proper balance or body control has hindered his effectiveness. He has struggled with his accuracy, and his disappointing completion percentage has raised red flags for some evaluators.

Don't forget about Dalton

Other passers might be getting more attention, but TCU's Andy Dalton found his way onto
Mike Mayock's ranking of the top five quarterback prospects. Check out the
entire list.

With so much uncertainty in the group, scouts are looking at the next tier of passers in hopes of uncovering a gem. This has pushed the likes of Nevada's Colin Kaepernick, Iowa's Ricky Stanzi and TCU's Andy Dalton up draft boards.

Given the quarterback's importance and the number of teams searching for a viable option, let's take a deeper look at the top five prospects at the position heading into the NFL Scouting Combine:

1. Blaine Gabbert, Missouri: He has emerged after posting a pair of 3,000-yard seasons. He is big (6-foot-5, 235 pounds) with outstanding arm strength and touch, and is capable of making all of the throws required in the pro game. His quick release and compact throwing motion enable him to get the ball out against pressure. He is regarded as a sound decision-maker, and his 40:16 touchdown-to-interception ratio backs up that assertion. While there are major concerns about his ability to transition from a spread offense to a more pro-style attack, his natural talent rates off the charts. He could emerge as the No. 1 quarterback prospect heading into the final phase of the evaluation period if he's able to accomplish a few things at the combine. He has to demonstrate good footwork, quickness and body control, while executing throws from three-, five- and seven step drops. He must also convince evaluators that he has the mental acumen to handle the complexities of running a pro system.Possible landing spots: Buffalo, Cincinnati, Arizona, San Francisco, Tennessee, Minnesota.

2. Cam Newton, Auburn: He is one of the most intriguing prospects due to his remarkable combination of size, speed and athleticism. He is coming off a sensational season at Auburn, where he led the SEC in rushing yards, amassed 30 touchdowns through the air and won a BCS National Championship. As a passer, he shows arm strength and touch, and has solid mechanics for a young player. He gets the ball out of his hand quickly on short and intermediate throws, while also displaying good accuracy when going downfield. He has the ability to drop the ball in the bucket on deep sideline tosses. Even though he has struggled at times with his accuracy from the pocket and on the move, his issues are correctable and not viewed as long-term impediments to his potential. If he can continue to develop his footwork and fundamentals, it would help his transition from a spread quarterback to a pro-style passer. He must also display the work ethic and study habits expected of a franchise quarterback. That package could push Newton up draft boards.Possible Landing Spots: Carolina, Buffalo, Tennessee, Washington and Miami.

3. Ryan Mallett, Arkansas: He has seemingly flown under the radar, but his exceptional size (6-6, 238 pounds), arm strength and skills have put him squarely on the map with so many teams desperately seeking a solution at quarterback. He is well schooled in the pro game following a two-year stint under Bobby Petrino, who has NFL coaching experience, and that time could give him a leg up on the competition. Mallett understands how to run the game from the line of scrimmage, and his ability to make proper checks helped him exploit blitz pressure for big gains. As a classic drop-back passer with a good pocket presence, Mallett has the potential to excel in the vertical passing game. He throws the deep ball with exceptional touch and accuracy, and his penchant for pushing the ball deep is rare for a young quarterback. Although questions regarding his maturity and work ethic will need to be addressed during the interview process, his skill set will warrant a first-round grade on most boards.Possible Landing Spots: Miami, Minnesota, Seattle, Cincinnati.

4. Jake Locker, Washington: He has been watched by scouts the past few years due to his extraordinary athleticism, movement skills and potential. As a dual-threat at quarterback, he shows promise working on the perimeter on bootlegs and movement passes. He throws the ball with good zip on the move and has above average accuracy when he keeps his mechanics in check. However, he often falls apart mechanically when working from the pocket. His accuracy issues stem from his inability to come to balance before he throws. The issues surfaced during his week at the Senior Bowl, when he had difficulty stringing together completions in drills. While Locker still rates as a top-40 talent, he will need to start showing gradual improvement as a passer to remain as one of the top quarterbacks in the class.Possible Landing Spots: Washington, Miami, San Francisco, Seattle.

5. Christian Ponder, Florida State: After falling out of the limelight following an injury-plagued senior season, Ponder has re-entered the conversation following his solid week at the Senior Bowl. He is a classic drop-back passer, but has good mobility and athleticism within the pocket. He displays good set-up quickness when working off conventional three-, five- and seven-step drops, and routinely delivers the ball on time. As a passer, he demonstrates arm strength and touch on intermediate and deep throws. He also shows good awareness and anticipation when leading receivers into open windows. With the majority of pro offenses employing some form of a West Coast system, Ponder will experience a late surge in his stock when coaches take a closer look at the game tape. If he checks out medically, expect to see Ponder drafted sooner than anticipated.Possible Landing Spots: San Francisco, Seattle, Washington.